Formal Equivalence Between Partitioned and Partition-Free Quenches in Quantum Transport

Abstract

In this paper, we review the partitioned and partition-free approaches to the calculation of the time-dependent response of a molecular junction to the switch-on of an arbitrary time-dependent bias. Using the nonequilibrium Green’s function formalism on different time contours, we derive a formal equivalence between these two approaches. This clarifies a recent result of Odashima and Lewenkopf (Phys Rev B 95:104301, 2017), which is valid for a static bias and single-level molecular structure, and extends it to arbitrary time-dependent biases and arbitrarily large molecular structures.